Channel state information transmission for multiple carriers

ABSTRACT

Channel state information is reported in periodic and aperiodic reports for multiple component carriers or serving cells. Channel state information may be reported for a subset of aggregated downlink carriers or serving cells. For an aperiodic report, the carrier(s)/serving cell(s) for which channel state information is reported are determined based on the request for the aperiodic report. When a CQI/PMI/RI report and a HARQ ACK/NACK report coincide in a subframe, the HARQ ACK/NACK report is transmitted on PUCCH, and the CQI/PMI/RI report is transmitted on PUSCH.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Non-provisional applicationSer. No. 15/179,195, filed Jun. 10, 2016, which is a continuation ofU.S. Non-provisional application Ser. No. 12/987,647, filed Jan. 10,2011, issued as U.S. Pat. No. 9,391,736, which claims the benefit ofU.S. Provisional Application No. 61/293,412, filed Jan. 8, 2010, U.S.Provisional Application No. 61/329,743, filed Apr. 30, 2010, U.S.Provisional Application No. 61/356,400, filed Jun. 18, 2010, U.S.Provisional Application No. 61/356,449, filed Jun. 18, 2010, and U.S.Provisional Application No. 61/389,057, filed Oct. 1, 2010, all of whichare hereby incorporated by reference herein.

BACKGROUND

In order to support higher data rate and spectrum efficiency, the ThirdGeneration Partnership Project (3GPP) Long Term Evolution (LTE) systemhas been introduced into 3GPP Release 8 (R8) (LTE Release 8 may bereferred to herein as LTE R8 or R8-LTE). In LTE, in order to schedulethe downlink (DL) transmission, the eNodeB relies on Channel QualityIndicator (CQI) reports transmitted by the User Equipment (UE) in theuplink (UL). Two modes of CQI reporting may be supported in LTE,aperiodic and periodic.

LTE Advanced (which includes LTE Release 10 (R10) and may include futurereleases such as Release 11, also referred to herein as LTE-A, LTE R10,or R10-LTE) is a further evolution of the LTE standard that provides a4G upgrade path for LTE and 3G networks. In LTE-A, carrier aggregationis supported, and, unlike in LTE, multiple component carriers (CCs) orserving cells may be assigned to the uplink, downlink, or both. Suchcarriers may be asymmetric. For example, different number of CCs may beassigned to the uplink than the number of CCs assigned to the downlink.

In LTE Release 8, channel state information (CSI) is designed to fit theoperation of simple single component carrier. A CSI report may includeCQI. With carrier aggregation, however, a wireless transmit receive unit(WTRU) may send a periodic channel quality report for multiple, such asfor up to the maximum number of downlink CCs that may be configured forthe WTRU, onto one WTRU-specific UL CC. Thus, in LTE-A, the amount ofperiodic feedbacks to be transmitted by a UE may increase considerablycompared to that of LTE Rel-8 on a given UL CC. Issues pertaining toperiodic CSI reporting in carrier aggregation may easily be extended toaperiodic CSI reporting. For example, a UE may be expected to send anaperiodic channel quality report for multiple DL CCs onto one WTRUspecific UL CC. However, current mechanisms may not accommodate theincreased demand in periodic and aperiodic CSI reporting. For example,current mechanisms may not support transmitting CSI for multiplecarriers over Physical Uplink Control Channel (PUCCH), transmit CSI overDFT-S-OFDM-based PUCCH, or multiplex certain CSI over PUCCH.

SUMMARY

Methods and systems for transmitting channel state information withcarrier aggregation are disclosed. Periodic and aperiodic CSIinformation for multiple component carriers (CCs) or serving cells maybe transmitted by a WTRU. In an embodiment, DL CSI may be reported for asubset of DL CCs or serving cells. For example, a DL CSI reportingcomponent carrier set or a set of DL CSI reporting serving cells may bea subset of DL CCs or serving cells, and may include the set of DL CCsor serving cells configured by higher layer for which a periodic and/oraperiodic CSI reports may be scheduled to transmit in the UL.

In an embodiment, an indication to transmit a CSI report may bereceived, and which serving cell or set of serving cells to base the CSIreport on may be determined based on the received indication. Forexample, the DL serving cell or set of DL CSI reporting serving cellsmay be determined based on a received DCI format or a received randomaccess response grant. A CSI report for the determined DL serving cellor set of DL CSI reporting serving cells may be transmitted.

The CSI report may include Hybrid Automatic Repeat reQuest (HARQ)ACK/NACK report and Channel Quality Indicator (CQI)/Precoding MatrixIndication (PMI)/Rank Indication (RI) report. In an embodiment, HARQACK/NACK report and CQI/PMI/RI report may be transmitted separately.Separate transmission of ACK/NACK and CQI may be used when there areinsufficient resources available in PUSCH to accommodate both ACK/NACKand CQI. For example, simultaneous transmission of PUCCH and PUSCH ispermitted or configured. When a CQI/PMI/RI report and an ACK/NACK reportcoincide in a subframe, the HARQ ACK/NACK may be transmitted on PUCCH,and CQI/PMI/RI may be transmitted on PUSCH. In an embodiment, PUSCHresources may be allocated to accommodate ACK/NACK reports and CQI/PMIor RI reports, and ACK/NACK and CQI/PMI or RI reports may be jointlytransmitted on PUSCH.

In an embodiment, resources on PUCCH may be allocated for transmittingCSI reports. For example, the number of resource blocks (RBs) allocatedfor a CSI report structure may be received. A schedule assigning theouter most RBs on the PUCCH for feedback transmission using the CSIstructure may be received. CSI feedback may be transmitted in the numberof outer most RBs in the CSI structure. These and additional aspects ofthe current disclosure are set forth in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

For the purposes of illustration, are exemplary embodiments shown in thedrawings; however, the subject matter is not limited to the specificelements and instrumentalities disclosed. In the drawings:

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented.

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A.

FIG. 1C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 1A.

FIG. 2 illustrates an example mapping of CQI/PMI, RI, and/or HARQACK/NACK on PUSCH.

FIG. 3 shows an example PUCCH configuration;

FIG. 4 shows example configurations for carrier aggregation;

FIG. 5 illustrates an exemplary process for reporting channel stateinformation with carrier aggregation.

FIG. 6 shows an example mapping of CQI/PMI, RI and data onto PUSCH.

FIG. 7 illustrates example opportunistic transmission of CSI formultiple carriers.

FIG. 8 illustrates a non-limiting exemplary PUCCH encoding chain for aDFT-S-OFDM based PUCCH transmission.

FIGS. 9-11 illustrate non-limiting exemplary encoding of HARQ ACK/NACK.

FIG. 12 illustrates a non-limiting exemplary control signal mapping fora DFT-S-OFDM-based PUCCH transmission.

FIG. 13 illustrates an example PUCCH configuration for resourceallocation on PUCCH.

FIG. 14 illustrates an example process for transmitting CSI feedback.

FIG. 15 shows an example PUCCH configuration.

FIG. 16 shows an example method for transmitting a CSI report.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems100 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a radioaccess network (RAN) 104, a core network 106, a public switchedtelephone network (PSTN) 108, the Internet 110, and other networks 112,though it will be appreciated that the disclosed embodiments contemplateany number of WTRUs, base stations, networks, and/or network elements.Each of the WTRUs 102 a, 102 b, 102 c, 102 d may be any type of deviceconfigured to operate and/or communicate in a wireless environment. Byway of example, the WTRUs 102 a, 102 b, 102 c, 102 d may be configuredto transmit and/or receive wireless signals and may include userequipment (WTRU), a mobile station, a fixed or mobile subscriber unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,consumer electronics, and the like.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106, the Internet 110,and/or the networks 112. By way of example, the base stations 114 a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a HomeNode B, a Home eNode B, a site controller, an access point (AP), awireless router, and the like. While the base stations 114 a, 114 b areeach depicted as a single element, it will be appreciated that the basestations 114 a, 114 b may include any number of interconnected basestations and/or network elements.

The base station 114 a may be part of the RAN 104, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown). The cell may further be divided into cell sectors. For example,the cell associated with the base station 114 a may be divided intothree sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, etc.). Theair interface 116 may be established using any suitable radio accesstechnology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104 and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 116 using wideband CDMA (WCDMA). WCDMAmay include communication protocols such as High-Speed Packet Access(HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed DownlinkPacket Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106.

The RAN 104 may be in communication with the core network 106, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. For example, the core network 106may provide call control, billing services, mobile location-basedservices, pre-paid calling, Internet connectivity, video distribution,etc., and/or perform high-level security functions, such as userauthentication. Although not shown in FIG. 1A, it will be appreciatedthat the RAN 104 and/or the core network 106 may be in direct orindirect communication with other RANs that employ the same RAT as theRAN 104 or a different RAT. For example, in addition to being connectedto the RAN 104, which may be utilizing an E-UTRA radio technology, thecore network 106 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106 may also serve as a gateway for the WTRUs 102 a,102 b, 102 c, 102 d to access the PSTN 108, the Internet 110, and/orother networks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) andthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired or wireless communications networks ownedand/or operated by other service providers. For example, the networks112 may include another core network connected to one or more RANs,which may employ the same RAT as the RAN 104 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 130, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In another embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and receive both RF and light signals. It will be appreciatedthat the transmit/receive element 122 may be configured to transmitand/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is a system diagram of the RAN 104 and the core network 106according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the core network 106.

The RAN 104 may include eNode-Bs 140 a, 140 b, 140 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 140 a, 140 b, 140c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 140 a, 140 b, 140 c may implement MIMO technology. Thus,the eNode-B 140 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode-Bs 140 a, 140 b, 140 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1C, theeNode-Bs 140 a, 140 b, 140 c may communicate with one another over an X2interface.

The core network 106 shown in FIG. 1C may include a mobility managementgateway (MME) 142, a serving gateway 144, and a packet data network(PDN) gateway 146. While each of the foregoing elements are depicted aspart of the core network 106, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 142 may be connected to each of the eNode-Bs 142 a, 142 b, 142 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 142 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 142 may also provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 144 may be connected to each of the eNode Bs 140 a,140 b, 140 c in the RAN 104 via the S1 interface. The serving gateway144 may generally route and forward user data packets to/from the WTRUs102 a, 102 b, 102 c. The serving gateway 144 may also perform otherfunctions, such as anchoring user planes during inter-eNode B handovers,triggering paging when downlink data is available for the WTRUs 102 a,102 b, 102 c, managing and storing contexts of the WTRUs 102 a, 102 b,102 c, and the like.

The serving gateway 144 may also be connected to the PDN gateway 146,which may provide the WTRUs 102 a, 102 b, 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and IP-enableddevices.

The core network 106 may facilitate communications with other networks.For example, the core network 106 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 106 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 106 and the PSTN 108. In addition, the corenetwork 106 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

To schedule the downlink (DL) transmissions, the eNodeB may rely onchannel quality indicator (CQI) reports transmitted by the WTRU 102 inthe uplink (UL). For MIMO transmissions, the WTRU 102 can be configuredto transmit Multiple Input Multiple Output (MIMO)-related feedbacktogether with the CQI report to assist the eNodeB in selecting anappropriate MIMO configuration for the DL transmissions. TheMIMO-related feedback signalling may include Precoding Matrix Indication(PMI) and Rank Indication (RI).

CQI may be reported periodically or aperiodically. An Aperiodic CQIreport may be transmitted on the Physical Uplink Shared Channel (PUSCH),while a periodic report may be transmitted on the Physical UplinkControl Channel (PUCCH) or on the PUSCH. When the WTRU 102 is allocatedPUSCH resources in one of the periodic subframes, the periodic CQIreport may be sent on the PUSCH. Moreover, the WTRU 102 can beconfigured to transmit both periodic and aperiodic reporting in the samesubframe. When this occurs, the WTRU 102 may transmit the aperiodicreport in that subframe. For example, in an embodiment, the WTRU 102 maytransmit only the aperiodic report in that subframe.

CQI feedback modes or feedback types may be configured through higherlayer signalling depending on how detailed the channel state feedback iseither needed or requested at the eNodeB. For example, CQI feedbacktypes may include wideband feedback, higher layer configured subbandfeedback, and/or WTRU-selected subband feedback. Table 1 summarizesexample reporting modes for aperiodic CQI reporting.

TABLE 1 CQI and PMI Feedback Types for aperiodic reporting on PUSCH PMIFeedback Type No Single Multiple PMI PMI PMI PUSCH CQI Wideband Mode 1-2Feedback (wideband CQI) Type WTRU Selected Mode 2-0 Mode 2-2 (subbandCQI) Higher Layer- Mode 3-0 Mode 3-1 configured (subband CQI)

Wideband feedback may be configured when coarse channel information isrequired at the eNodeB. Also, when there are a large number of scheduledUEs, a wideband report may be used.

When a frequency selective report is needed or requested at eNodeB, theWTRU 102 can be configured to provide a subband-based feedback wherein aseparate CQI, or PMI, may be reported for each sub-band. To reducefeedback overhead, a scheme based on the spatial differential CQI may beused. According to this scheme, for the PUCCH-based periodic reporting,the difference between the wideband CQIs of two codewords may bedifferentially encoded using 3-bits. For example, Codeword 1 offsetlevel may be defined as wideband CQI index for codeword 0-wideband CQIindex for codeword 1.

For PUSCH-based periodic reporting, the subband CQI values for eachcodeword may be encoded differentially with respect to their respectivewideband CQI using 2 bits. For example, Subband differential CQI offsetlevel may be defined as subband CQI index-wideband CQI index.

When the WTRU 102 has a valid scheduling grant in a subframe, in whichthe WTRU 102 may transmit control signalling, the control signalling maybe time multiplexed with data on the PUSCH. Example mappings of CQI/PMI,RI and HARQ ACK/NACK on PUSCH are shown in FIG. 2. As shown, resourceblocks (RBs) 205 may be transmitted over slot 0 206, and slot 1 270over, for example, 1 ms. The HARQ ACK/NACK 220 may be transmitted onresources next to the PUSCH reference symbols (RS) 210. The RI 230 maybe mapped next to the resources reserved for ACK/NACK 220 transmission.The coding of the ACK/NACK 220 and RI 230 may be based on repetitioncoding or simplex coding with optional circular repetition. In anembodiment, to meet the performance targets for ACK/NACK 220 and RI 230transmissions, a substantial portion of PUSCH resources may be devotedto 1-bit or 2-bit ACK/NACK 220 and RI 230.

In case of collision between CQI/PMI/RI and ACK/NACK in a same subframe,CQI/PMI/RI may be dropped if the parameter simultaneousAckNackAndC

I provided by higher layers is set to FALSE. CQI/PMI/RI may bemultiplexed with ACK/NAK otherwise. The periodic CQI report may betransmitted on the resource n_(PUCCH) ⁽²⁾ configured by higher layersand using PUCCH format 2/2a/2b. The number of reserved resource blocks(RBs) for PUCCH 2/2a/2b may be configured by the higher-layer parameter,N_(RB) ⁽²⁾, while the total number of RBs available for PUCCHtransmission within the cell may be specified by the higher layerparameter, N_(RB) ^(HO).

FIG. 3 illustrates an example the PUCCH configuration. RBs 310 may bethe RBs reserved for the PUCCH as configured by N_(RB) ^(HO). Among RBs310, RBs 320 may be reserved for PUCCH format 2/2a/2b as configured byN_(RB) ⁽²⁾. Also among RBs 310, RB 330 may be a mixed RB that may beused for both PUCCH format 1/1a/1b and format 1/2a/2b, as may beconfigured by N_(CS) ⁽¹⁾. Further among RBs 310, RBs 340 may beresources that may be reserved for persistent PUCCH format 1/1a/1b asconfigured by N_(PUCCH) ⁽¹⁾. Also among RBs 310, RBs 350 may beresources reserved for dynamic PUCCH format 1/1a/1b. In an embodiment,for PUCCH format 1/1a/1b the resource index n_(PUCCH) ⁽¹⁾ may determinethe orthogonal sequence index and/or the corresponding value of thecyclic shift within each RB.

To maximize the bandwidth utilization, PUSCH and PUCCH may betransmitted in the same subframe simultaneously. This may avoid thebandwidth loss incurred by dropping the RBs reserved for PUCCHtransmission when the WTRU 102 is scheduled for data transmission on thePUSCH in a given subframe. More specifically, by enabling the concurrenttransmission of PUCCH and PUSCH in a subframe, the WTRU 102 can sendcontrol information on the PUCCH resources while data packets would besent on PUSCH rather than multiplexing of control signalling and UplinkShared Channel (UL-SCH) data on PUSCH. This may free up the PUSCHresources for data transmission.

Carrier aggregation, where two or more component carriers (CCs) areaggregated, may support wider transmission bandwidths, e.g. up to 100MHz. CCs may also be referred to as serving cells, and the terms areused interchangeably herein. In an embodiment, a CC may include one ormore serving cells. In an embodiment, a serving cell may include one ormore CCs. Carrier aggregation may also be referred to as serving cellaggregation, and the terms are used interchangeably herein.

The WTRU 102 may aggregate a different number of CCs, or serving cellsof different or same bandwidths in the UL and the DL. The set of DL CCsor set of DL serving cells on which a WTRU 102 may be scheduled toreceive the Physical Downlink Shared Channel (PDSCH) in the DL may beconfigured by dedicated signaling.

Three example configurations for carrier aggregation are illustrated inFIG. 4. In configuration 410, symmetric carrier aggregation isillustrated, where there are the same number of component carriers usedfor both UL and DL. Configuration 420 illustrates the use of more DLcomponent carriers than UL component carriers. In the illustratedexample, two component carriers for DL are shown and one for UL. Inconfiguration 430, the opposite scenario is shown, with two componentcarriers in used for UL and one for DL. Any other combination and numberof component carriers for UL and DL are contemplated as within the scopeof the present disclosure.

With carrier aggregation, channel state information (CSI) which mayinclude CQI/PMI/RI may be fed back by the WTRU 102 for multiple CCs ormultiple serving cells. In an embodiment, periodic CSI reporting for upto the maximum number of downlink CCs/serving cells that may beconfigured for the WTRU, may be supported. Periodic CSI reporting may bemapped onto a WTRU-specific UL CC semi-statically. For example, mappingof CSI reporting may be signaled via dedicated signaling or a higherlayer signaling, such as RRC signaling.

CQI reporting of multiple CCs or multiple serving cells on a single ULCC may be implemented in several ways, such as cycling through bothbandwidth parts and CCs or serving cells, reporting the wideband CQI, orbest subband CQI, corresponding to multiple BW parts in a given CC,reporting the wideband CQI, or best subband, within a set of BW partsacross multiple CCs or multiple serving cells, and/or reporting the CQIsfor CCs or serving cells within WTRU DL CC set or set of DL servingcells in the same reporting instance.

Alternatives for the support of larger PUCCH CQI payload per reportinginstance may include, but not limited to, using multiple PUCCH Format 2resources, using PUSCH for periodic reporting, and/or using new CQIstructures with increased payload size.

Extending CSI payload may be accomplished using a modified CSIstructure. The increased CQI payload size can be realized bymodification of the PUCCH or using PUSCH resources. Separate RBs may beallocated for the newly CQI structure, and backward compatibility may bemaintained.

In an embodiment, DL CSI may be reported for a subset of DL CCs orserving cells to reduce reporting overhead. For example, a DL CSIreporting CC set or set of DL CSI reporting serving cells may bedefined. CC set may also be referred to as set of serving cells, and theterms are used interchangeably herein. A WTRU DL CQI/PMI/RI reporting CCset may be defined to reduce the amount of feedback to be reported bythe WTRU 102 for multiple CCs in a reporting instance. A CC set or setof serving cells may include a set of DL CCs or serving cells configuredby dedicated signaling for which the WTRU 102 may be scheduled totransmit a periodic and/or aperiodic CSI report(s) in the UL. The CSIreporting CC set may include a subset of the WTRU DL component carrierset. The WTRU 102 may transmit CSI reports for a subset of the DL CCs orDL serving cells configured by dedicated signalling. For example, theWTRU 102 may transmit feedback for CCs/serving cells that may be part ofthe DL CSI reporting CC set or set of DL CSI reporting serving cells(RCCS).

The DL CSI RCCS may be configured by higher layer signalling. Forexample, higher layer may configure DL CSI RCCS via a configurationparameter such as cqi-ReportComponentCarrierSet. The parameter may beincluded in IE C

I-ReportConfig as follows:

CQI-ReportConfig_R10 ::= SEQUENCE { cqi-ReportComponentCarrierSet BITSTRING (SIZE (5)) OPTIONAL, cqi-ReportModeAperiodic ENUMERATED { rm12,rm20, rm22, rm30, rm31, spare3, spare2, spare1} OPTIONAL,- Need ORnomPDSCH-RS-EPRE-Offset INTEGER (−1..6), cqi-ReportPeriodicCQI-ReportPeriodic OPTIONAL - Need ON }

In an embodiment, two separate DL RCCS's may be defined for differentCSI reporting modes (e.g., one for periodic a reporting mode, and onefor a aperiodic one). For example, the RCCS's may include a set of DLcomponent carriers/serving cells configured by dedicated signaling forwhich the WTRU 102 may be scheduled to transmit a periodic CSI report inthe UL. The periodic reporting CC set/set of serving cells may include asubset of the WTRU DL CC set. The RCCS's may include a set of DLcomponent carriers/serving cells configured by dedicated signaling forwhich the WTRU 102 may be scheduled to transmit an aperiodic CSI reportin the UL. The aperiodic reporting CC set/set of serving cells mayinclude a subset of the WTRU DL CC set/set of serving cells.

For example, when a detailed channel information feedback report for oneor multiple CC(s) within a WTRU's configured CC set is not required ateNodeB, the WTRU 102 may be configured exclude those CCs' feedback inits aperiodic report to maximize the bandwidth utilization. For example,when the eNodeB experiences a large feedback overhead due to a largenumber of users in the system, the eNodeB may decide to limit theoverhead by configuring a periodic report for a subset of CCs withineach WTRU's configured DL CC set. This may enhance the flexibility atthe eNodeB for reporting configurations.

Periodic and aperiodic CSI RCCS's may be configured by higher layersignaling, for example, via two configuration parameters such ascqi-ReportComponentCarrierSetPeriodic andcqi-ReportComponentCarrierSetAperiodic. For example, the parameters maybe included in IE C

I-ReportConfig as follows:

CQI-ReportConfig_R10 ::= SEQUENCE {cqi-ReportComponentCarrierSetPeriodic BIT STRING (SIZE (5)) OPTIONAL, cqi-ReportComponentCarrierSetAperiodic BIT STRING (SIZE (5)) OPTIONAL,cqi-ReportModeAperiodic ENUMERATED { rm12, rm20, rm22, rm30, rm31,spare3, spare2, spare1} OPTIONAL,- Need OR nomPDSCH-RS-EPRE-OffsetINTEGER (−1..6), cqi-ReportPeriodic CQI-ReportPeriodic OPTIONAL -Need ON}The CSI RCCS may be configured via a bit map using, for example, fivebits, assuming five component carriers are supported. The CSI RCCS maybe configured using a predetermined number of bits depending on thenumber of DL configured component carriers.

In an embodiment, periodic and aperiodic reporting may be transmittedconcurrently in the same subframe. For example, when both periodic andaperiodic reporting occur in the same subframe, both periodic andaperiodic reports may be transmitted in that subframe.

When both periodic and aperiodic reports are related to the same DL CCor serving cell, the WTRU 102 may transmit aperiodic report. Theperiodic report may be dropped. When periodic and aperiodic reportscorrespond to different CCs/serving cells, the WTRU 102 may transmitboth periodic and aperiodic reports in that subframe. The WTRU 102 maytransmit a periodic feedback for one or more CC(s) within the componentcarrier set of the WTRU 102 while an aperiodic report may be transmittedfor other CC(s) within the set.

FIG. 5 illustrates an exemplary method of reporting channel stateinformation with carrier aggregation. As shown, at 510, an indication totransmit an aperiodic CSI report may be received. In an embodiment, arequest for an aperiodic report of CSI information such as CQI, PMIand/or RI may be received. For example, the indication to transmit anaperiodic CSI report may be received in a subframe such as subframe n.In an example, the WTRU 102 may receive a downlink control information(DCI) format 0 in sub-frame n. A DCI format may grant resources for anuplink transmission on PUSCH. In the DCI format, the CQI request fieldmay be set to 1. In an example, the WTRU 102 may receive a Random AccessResponse Grant in sub-frame n. In the Random Access Response Grant, theCQI request field may be set to 1 in the case of a non-contention basedrandom access procedure. Based on the indication, the WTRU 102 maydetermine that the WTRU 102 should perform aperiodic CQI, PMI, and/or RIreporting on PUSCH in a sub-frame, such as subframe n+k. In anembodiment, k may equal to 4 for FDD.

As shown in FIG. 5, at 530, a serving cell or a set of serving cells forwhich CSI may be reported may be determined. The WTRU 102 may determinethe serving cell or set of serving cells for which CQI, PMI, RI or anycombination thereof may be reported according to at least one of thefollowing methods. For example, the determination may be based on thereceived indication, such as the content of the received DCI or thereceived.

In an embodiment, the DL serving cell or set of DL serving cells may bedetermined upon decoding the indication received in subframe n. Asdescribed above, the indication received may include an uplink DCIformat, and/or a Random Access Response Grant. The DL serving cell orset of DL serving cells may be determined based on the UL grantcontained in the received DCI format or in the received Random AccessResponse Grant. For example, the DL serving cell or set of DL servingcells may include the serving cell(s) of the PUSCH transmissionindicated by the UL grant, e.g. in the received uplink DCI format or thereceived Random Access Response Grant. For example, the received uplinkDCI format or the received Random Access Response Grant may include afield such as a CSI request field, a CQI request field or the like. Thefield may include a value indicative of whether aperiodic CSI report istriggered, and/or the DL serving cell or set of DL serving cells forwhich CSI report is triggered.

For example, the DL serving cell or set of DL serving cells maycorrespond to DL serving cell(s) associated with a UL serving cell(s)for which the UL grant may apply. The UL serving cell(s) may include aPcell and/or a Scell. The association may be provided by higher layer(RRC) signaling, and may be indicated either in a dedicated way orbroadcast in the system information (SIB2 linking) of the DL servingcell(s).

In an embodiment, the UL grant signaled by the DCI may not result in anactual transmission. For example, the UL grant signaled by the DCI maycorrespond to a non-configured UL serving cell(s). The UL grant signaledby the DCI may have the same fields as a grant indicating transmissionof uplink control information (UCI) without UL-SCH data, or withouttransport block. For example, the fields may include values such thatIMCS=29 and NPRB<=4. The UL grant signaled by the DCI may have fieldsset according to specific values to indicate that the purpose of thegrant is the indication of a DL serving cellset of DL serving cells forwhich CSI is to be reported. For instance, the fields may include valuessuch that NPRB=0. When the UL grant signaled by the DCI does not resultin an actual transmission, the CSI (along with the other UL controlinformation) may be transmitted in another UL serving cell(s) accordingto a pre-determined rule. The rule may be the same rule as when the UCIthat may include ACK/NACK feedback (e.g., include in PUSCH of Pcell ifpresent). In case the WTRU 102, in a given subframe, detects UL grant(s)that may not correspond to an actual transmission, the WTRU 102 may notreport any aperiodic CSI in PUSCH in subframe n+k.

In an embodiment, the DL serving cell or set of DL serving cells maycorrespond to for example, e.g. Pcell and/or Scell, for which the ULgrant contained in the DCI format or in the random access response mayapply. In an embodiment, the DL serving cell or set of downlink servingcells may correspond to the DL serving cell(s) of the Physical DownlinkControl Channel (PDCCH) on which the DCI format or random accessresponse may be decoded. This may apply to DCI formats, or to DCIformats that may not a carrier indication field (CIF). In an embodiment,the DL serving cell or set of DL serving cells may correspond to the DLserving cell(s) of the Physical Downlink Shared Channel (PDSCH) on whichthe random access response may be decoded. In an example method, the DLserving cell or set of DL serving cells may be determined based on thedecoding location of the DCI format according to definedcarrier-specific or serving cell-specific search space(s).

The configured DL serving cells, or a subset of configured serving cellsfor which CSI is reported in an aperiodic report, may be configured byhigher layers. For example, the subset of DL serving cells for whichreporting is performed may correspond to the subset of configured DLserving cells for which no periodic CSI reporting is performed.

In an example method, a set of subframes may be defined for the DLserving cell or set of DL serving cells for which a CSI report may betransmitted. The set of subframes may be defined using subframe numbers,frame numbers or a combination thereof, along with other parameters thatmay be configured by higher layers. For instance, in the case of Nconfigured carriers/serving cells, the set of subframes for the jth DLserving cell may be defined as subframes satisfying (10 Nf+Ns+offset)modulo N=j where Nf is the system frame number, Ns is the subframenumber and offset is a parameter configured by higher layers. Forexample, the WTRU 102 may transmit a CSI report for a DL serving cell,if the subframe in which the indication to transmit the aperiodic reportis received, belongs to the set of subframes defined for the DL servingcell. For example, the WTRU 102 may transmit a CSI report for a DLserving cell, if the subframe in which the aperiodic report is to betransmitted belongs to the set of subframes defined for the DL servingcell. In the case of two DL serving cells, CSI report for one servingcell may be transmitted if the aperiodic report is transmitted in aneven subframe, and CSI report for the other serving cell may betransmitted if the aperiodic report is transmitted in an odd subframe.

In an example method, the DL serving cell or set of DL serving cells maybe determined based on an indication in the DCI format or in a randomaccess response grant with the CQI request that may be received insubframe n. For example, this indication may be the carrier indicationfield (CIF) and/or the CSI Request field. The mapping between indicationand the DL serving cell or set of DL serving cells may be provided byhigher layers. For example, the DL serving cell may be directlyindicated via the CIF field. The DL serving cell may be the DL servingcell associated to the UL carrier indicated by the CIF. A specificcodepoint may indicate that the set of DL serving cell(s) to report maybe determined using another method. For instance, upon reception of aspecific codepoint, the WTRU 102 may determine the set of DL servingcells based on the subframe timing. In an embodiment, upon reception ofa first specific codepoint for the CSI request field, the WTRU 102 maydetermine that the DL serving cell may include the serving cell of thePUSCH transmission indicated by the UL grant, for example, in an uplinkDCI format or a random access response grant. In an embodiment, uponreception of a specific codepoint for the CSI request field, the WTRU102 may determine that the set of serving cells may include acorresponding set configured by higher layers.

The indication for DL serving cell or set of DL serving cells may alsobe conveyed by reusing or replacing a field, or a subset of bits orcodepoints of a field in the DCI format. Re-interpretation may takeplace when the “CQI request field” that CSI is being requested. Forinstance, fields that may be reused or re-interpreted, alone or incombination, may include the “TPC command for scheduled PUSCH” field,the “Resource block assignment and hopping resource allocation” field,the “Modulation and coding scheme and redundancy version” field, and/orthe “Cyclic shift for DM RS” field. In an embodiment, other controlfields may also be reused or re-interpreted to indicate DL serving cellor set of DL serving cells for which CSI may be reported.

When a field is reused for the purpose of indicating the DL serving cellor the set of DL serving cell(s) to report for, the WTRU 102 may behavedifferently with respect to the functionality originally associated withthis field. In an embodiment, the WTRU 102 may take no action withrespect to the original functionality. For instance, in case of reuse ofthe TPC bits the WTRU 102 may refrain from applying any power controladjustment.

In an embodiment, the WTRU 102 may behave as if the value indicated bythe reused field was a pre-defined value, or a value signaled by higherlayers. For instance, in case the “Cyclic shift for DM RS” is reused,the WTRU 102 may behave as if the “cyclic shift for DM RS” field was setto “000” or to a value provided by higher layers. This value may also bedependent on the UL carrier to which the grant may apply.

In an embodiment, the WTRU 102 may behave as per the originalinterpretation, with respect to the existing functionality, for certainvalues of the received codepoint. For instance, in the case of the“resource block assignment and hopping resource allocation” field isreused, the WTRU 102 may interpret any codepoint that may haverepresented a valid assignment as per the original interpretation.

In an embodiment, a codepoint that may not correspond to a valid ordefined codepoint with respect to the original functionality, may bemapped to a valid value or behavior. For instance, in the case of the“resource block assignment” field is reused, codepoints that do notrepresent a valid assignment as per the original interpretation may bemapped to a valid assignment. The WTRU 102 may re-interpret the field,or a subset of the bits thereof, according to a mapping related to theexisting functionality. For example, in case the “TPC command forscheduled PUSCH” field is reused, the first bit of this field may stillbe interpreted by the WTRU 102 as a power adjustment value. In anembodiment, the WTRU 102 may associate a timing relationship with theinterpretation of one or more of the fields.

The DL serving cell or set of DL serving cells may be determined basedon whether the aperiodic request may be received in a random accessresponse. For instance, in case the request is received in a randomaccess response, the DL serving cell set may include the primary carrieror primary serving cell such as Pcell. The DL serving cell set mayinclude the DL serving cell of the PDSCH on which the random accessresponse may be decoded. The set of DL serving cells may include the DLserving cell(s) of configured cells, or activated cells. The set of DLserving cells may include the DL serving cell(s) of a subset ofconfigured or activated cells that may be indicated by a field containedin the Random Access Response Grant.

In an embodiment, a subset of n DL serving cells may be determined. Thenumber of the DL serving cells in the subset, n, may be defined orconfigured by higher layers. The subset of DL serving cells may includea DL serving cell for which the CQI is the highest among the DL servingcells. DL serving cells which are currently not in active time, or in ade-activated state, may be excluded from the sequence.

As shown in FIG. 5, at 540, a CSI report for the determined DL servingcell or set of DL serving cells may be transmitted. In an embodiment, areporting order or sequence may be defined for the DL serving cells orsets of DL serving cells. The DL serving cell to report for may bedetermined by cycling through a defined order or sequence. For example,the DL serving cell or set of DL serving cells to be reported for may bedefined as the next DL serving cell(s) in the sequence of, the DLserving cell last reported in an aperiodic report, the DL serving celllast reported in a periodic report, and/or the DL serving cell lastreported in any report (periodic or aperiodic report). DL serving cellsthat may not be in active time, or in a de-activated state, may beexcluded from the sequence.

More than one DCI's may request CSI reporting for serving cell(s) in onesub-frame. In an embodiment, the WTRU 102 may not report the CSI of anyDL serving cell. For example, the WTRU 102 may consider a request thatcorrespond to more than one DL serving cells as an error case. In anembodiment, the WTRU 102 may report the CSI of one DL serving cell, orone set of DL serving cells according to a DCI selected from apredetermined rule. For example, the DCI may be selected based on the DLserving cell where the DCI was decoded.

In an embodiment, the WTRU 102 may report the CSI of DL serving cells,or sets of DL serving cells, indicated by each DCI according to one or acombination of the previously described embodiments. In an embodiment,the WTRU 102 may not include the report for a DL serving cell at thesubframe where the aperiodic request is received or in the subframewhere the reporting is to be made, even if it would otherwise haveaccording to one of the previous methods, when one or a combination ofconditions are met as described later in the context of determiningwhether a DL serving cell should be excluded from CSI reporting.

The amount of information available for aperiodic CQI/PMI/RI reportingin a subframe may be limited by one or more factors. For example,information may be limited by a maximum number of DL serving cells forwhich reporting may be made, which may be signaled by higher layers.Information may be limited by a maximum number of information bits, orcoded bits, or symbols, which may be a function of the modulation/codingscheme, number of resource blocks for PUSCH, grant, presence of HARQ-ACKinformation, or a combination thereof.

When an aperiodic report is to be transmitted for more than one DLserving cell, and the information is to be transmitted in more than onesubframe, the WTRU 102 may determine the CQI/PMI/RI of which DL servingcell(s) may be reported. The WTRU 102 may determine which serving cellis to be dropped for the subframe, according to at least one priorityrule that will be described below.

When an aperiodic report should be transmitted for more than one DLserving cell according to one of the above embodiments, and when due toa limitation such as the ones described in the above it is not possibleto report all information in a subframe, the WTRU 102 may determine theCQI/PMI/RI of which serving cell(s) may be reported. The WTRU 102 maydetermine the CQI/PMI/RI of which serving cell(s) is to be dropped forthe subframe, according to at least one priority rule described below.

In an embodiment, multiple CSI reports may be transmitted in a singlesubframe. For example, the CQI/PMI/RI information of more than one DLserving cell or component carrier may be reported in a subframe. The CSIreports may be concatenated first and then jointly encoded. The reportsmay be separately encoded and the coded bits/symbols may beconcatenated. The identity of the DL serving cell or component carriermay be included along with the respective report when multiple reportsare included into the same subframe.

In an embodiment, a predetermined order and/or location of eachconcatenated CSI report may be known to both the WTRU 102 and the eNB140. The WTRU 102 may generate the CSI reports based on thepredetermined order or location of the concatenated reports, and thereceiving eNB 140 may process the CSI reports based on the predeterminedorder or location. In an embodiment, the corresponding identity of theDL serving cell or component carrier may not be included along with therespective report.

In an embodiment, when multiple CSI reports of more than one DL servingcell or component carrier are reported in a single subframe, informationbits can be jointly encoded using tail biting convolutional coding(TBCC) encoding scheme. Other encoding schemes, such as Reed-Muller (RM)encoding scheme may also be used. In an embodiment, multiple encodingscheme may be used. TBCC may be more suitable for encoding large numberof information bits, and RM may be more suitable when a small number ofinformation bits are encoded. As such, combining multiple encodingschemes may improve performance.

In an embodiment, a triggering method for using different encodingschemes may be applied. Single threshold or multiple thresholds may beused to determine which encoding scheme(s) may be utilized.

In an embodiment, the total size of the multiple reports to betransmitted in a subframe may compared against a threshold value. Forexample, the WTRU may determine to use a particular encoding scheme suchas TBCC when the size of information bits to be encoded equals to orexceeds the threshold value. When the size of information bits to beencoded exceeds threshold value is less or equals to the thresholdvalue, the WTRU may determine to use a different encoding scheme such asRM. Multiple CSI reports for more than one DL serving cell or componentcarrier transmitted in a single subframe may be carried on PUSCH. In anembodiment, the PUSCH may carry control information when multiple CSIreports for more than one DL serving cell or component carriertransmitted in single subframe may be carried on the PUSCH. In anembodiment, the PUSCH may carry other information along with the CSIreports.

In an embodiment, the size of each of the multiple reports to betransmitted in a subframe may be compared against a threshold value. Asdescribed above, when multiple CSI reports of more than one DL servingcell or component carrier are reported in a single subframe, informationbits can be separately encoded. Different CSI reports may be encodedusing different encoding schemes. A single or multiple threshold-basedtriggering mechanism for encoding schemes may be applied to separateencoding of reports. For example, the WTRU 102 may determine to use aparticular encoding scheme such as TBCC for a first report when the sizeof the first report exceeds the threshold value. The WTRU 102 maydetermine to use a particular encoding scheme such as RM for a secondreport when the size of the first report equals to or is less than thethreshold value.

In an embodiment, the WTRU 102 may determine the DL serving cell or setof DL serving cells, for which periodic reporting of CQI/PMI/RI may beperformed in a given subframe, along with the type of reports in thissubframe. For example, the WTRU 102 may first determine, for each DLserving cell, the type of report (if any) that may be transmitted in agiven subframe, subject to restrictions to be described later. Forinstance, there may be a separate periodic CQI reporting configuration(including indices determining periodicities and offsets of differenttypes of report) with distinct parameter values for each DL servingcell. In an embodiment, the WTRU 102 may not include the report for a DLserving cell, even if it would otherwise have according to one of theprevious methods, when one or a combination of conditions are met asdescribed in the context of determining whether a DL serving cell shouldbe excluded from CSI reporting.

In an embodiment, the WTRU 102 may determine that in this subframereports for more than one DL serving cell may be transmitted. This couldhappen for instance if the reporting configurations for the periodicreporting of two DL serving cells are such that they are both configuredto be reported in a particular subframe. The amount of informationrequired to transmit these multiple reports may exceed the maximumamount of information that can be carried in this subframe (by e.g. aPUCCH or PUSCH resource assigned to the WTRU 102). The number of DLserving cells for which a report may be transmitted may exceed a definedmaximum number of DL serving cells for which reports can be made in asingle subframe. The WTRU 102 may transmit a subset of the reportsinitially determined for transmission into the subframe. The WTRU 102may select the subset of report(s) that may be transmitted in thesubframe according to at least one priority rule that will be describedbelow. The identity of the DL serving cell may be included along withthe respective report. The identity of the DL serving cell may beincluded along with the respective report when multiple reports areincluded into the same subframe.

Aperiodic reporting or periodic reporting may be prioritized based onone or more rules. For example, the priority between reports ofdifferent DL serving cells may be determined based on a priority orderprovided by higher layers. For instance, the order may be based on theorder in the RRC configuration, or according to an explicit indicationfor each DL serving cell. For example, the report for the primarycarrier (or serving cell), such as Pcell, may have higher priority thanthe secondary carriers such as Scells.

The priority between reports of different DL serving cells may bedetermined based on the type of report being transmitted for each DLserving cell. For instance, a Type 3 report that may carry RI feedbackmay have higher priority than a Type 1, Type 2 or Type 4 report that maycarry subband CQI, wideband CQI/PMI and wideband CQI respectively. Thereport may then be prioritized such that the primary carrier (or servingcell), Pcell may have higher priority than the secondary carriers orScells. A wideband CQI/PMI report may carry a higher priority than asubband CQI report. If simultaneous transmission of PUCCH and PUSCH issupported, a report on PUCCH may have a higher priority than a report onPUSCH in the same subframe.

The RI information may be prioritized over CQI/PMI information. Suchprioritization may be performed before prioritization between DL servingcells.

The priority between reports of different DL serving cells may bedetermined based on the reporting mode configured for each DL servingcell, PUSCH CQI feedback Type, and/or PMI feedback type. For instance,carriers configured with reporting mode 1-2 may have higher prioritythan carriers configured with reporting mode 2-2. The priority betweenreports of different DL serving cells may be determined based on thetransmission mode configured for each DL serving cell. The DL servingcells, for which a report may have been dropped in a previous subframe,and for which no report has been transmitted since then, may have higherpriority than other DL serving cells. The priority between reports ofdifferent DL serving cells may be determined based on the time since anaperiodic report, a periodic report, or a periodic or aperiodic reportis last transmitted for the DL serving cell. For instance, a DL servingcell for which a report has not been transmitted for a longer period oftime may have higher priority. In an embodiment, the time since anaperiodic report for CQI, PMI, and/or RI may be different. For example,CQI and or PMI may be sent more frequently than RI.

The priority among reports of different DL serving cells may bedetermined based on the time since either a periodic or aperiodic reportis sent for the Primary Carrier or Pcell. The priority may be based onthe amount of change in CQI, PMI, and/or RI since the last transmissionof a report for a DL serving cell. For instance, a DL serving cell forwhich the CQI has changed by a larger amount may have higher priority.The priority among reports of different DL serving cells or sets ofserving cells may be determined based on a corresponding configurationindex that may indicate periodicity and offset, such as the value ofI_(CQI/PMI). The configuration index I_(CQI/PMI) may be provided byhigher layers, and may include an index for a CQI/PMI report, given by aparameter such as parameter cqi-pmi-ConfigIndex. The priority amongreports of different DL serving cells or serving cells may be determinedbased on a corresponding configuration index such as index I_(RI). Theconfiguration index I_(RI) for a rank indication may be provided byhigher layers, and may include an index for an RI report, given by aparameter such parameter ri-ConfigIndex. For instance, an (activated)serving cell or DL serving cell for which the value of I_(CQI/PMI) maybe highest among a set of (activated) serving cells or DL serving cellsmay have the highest priority. This may provide a prioritizationcriterion between serving cells or DL serving cells that are reportedwith the same periodicity but possibly different offsets.

The priority between reports of different DL serving cells may bedetermined based on the CQI value of each DL serving cell. For instance,a DL serving cell with a higher CQI may have higher priority. Forexample, when periodic CSI reports for multiple DL serving cells are tobe transmitted, the respective CQI values of the DL serving cells maydetermine the priority of the reports. For example, the report for theDL serving cell may be reported if the CQI is above a threshold. Thiscriterion may be applicable in the case of WTRU-selected sub-bands. Forexample, a DL serving cell for which a wideband CQI reference value maybe applicable for a subsequent sub-band differential feed-back report.

The priority between reports of different DL serving cells may bedetermined based on the amount of change in CQI/PMI/RI since the lasttransmission of a report for a DL serving cell. For instance, a DLserving cell for which the CQI has changed by a larger amount may havehigher priority. The priority between reports of different DL servingcells may be determined based on the frequency bands that the DL servingcells belong to. For instance, the DL serving cells may be selected suchthat the number of frequency bands that DL serving cells reported for inthe subframe may be maximized.

In an embodiment, multiple priority rules for the reporting ofCQI/PMI/RI of different serving cells may be applied. For example, apriority rule based on the report type may be defined and applied at thesame time as a priority rule based on serving cells. In an embodiment,the priority rule based on the report type may have higher precedencethan the priority rule for the selection between different servingcells. For instance, RI may be scheduled to be reported in a subframefor a first serving cell, while CQI/PMI may be scheduled to be reportedin the same subframe for a second serving cell. The RI of the firstserving cell may have higher priority even if the first serving cell haslower priority than the second serving cell according to a cellprioritization rule. A cell prioritization rule may select the servingcell that is configured to be reported with the largest periodicity. Inan embodiment, the cell prioritization rule may have higher precedencethan the priority rule based on the report type. For instance, RI may bescheduled to be reported in a subframe for a secondary serving cell,while CQI/PMI may be scheduled to be reported in the same subframe forthe primary serving cell. The CQI/PMI of the primary serving cell mayhave higher priority even if RI type has higher priority than CQI/PMItype according to the report type priority rule. In an embodiment, thecell prioritization rule may have higher precedence than the report typepriority rule when one of the serving cells is the primary serving cell,and may have lower precedence than the report type priority rule whenthe serving cells are secondary cells.

In an embodiment, the WTRU 102 may determine whether a DL serving cellshould be excluded from CSI reporting. For example, the WTRU 102 mayexclude the CSI report for a DL serving cell that otherwise havereported, in the subframe where an aperiodic request is received, or inthe subframe where periodic or aperiodic reporting of CQI/PMI/RI is tobe made. For example, the WTRU 102 may exclude a DL serving cell fromCSI reporting when the DL serving cell is not in active time, when theDL serving cell is in a de-activated state, when the period of timesince a transmission (or new transmission) is received for this DLserving cell exceeds a threshold, and/or when the CQI, PMI, and/or RIhas not changed by an amount higher (e.g. in absolute value) than athreshold since it was last reported for this DL serving cell. For anaperiodic report, the WTRU 102 may exclude a DL serving cell that hasbeen configured for periodic CQI/PMI/RI reporting. The WTRU 102 mayexclude a DL serving cell when the period of time since a report(periodic, aperiodic, or any report) has been transmitted for this DLserving cell is below a threshold (e.g. prohibit timer). This may beapplicable to DL serving cells in de-activated state.

In an embodiment, payload ambiguity may be reduced or removed. Forexample, payload ambiguity may occur when sending an amount of CQIinformation unknown to the network. Payload ambiguity may be reduced orremoved by padding bits to the CQI reports such that the number oftransmitted CQI information bits may be predictable to the network.Payload ambiguity may be reduced or removed by pre-pending the CQIinformation with a size indicator field or a field indicating how manyDL serving cells are reported, and/or by pre-pending or appending acyclic redundancy check field to enable blind detection of the number ofCQI information bits by the network.

In an embodiment, a transmission mode may be used to transmit widebandCQI-only reporting for carrier aggregation. A wideband CQI-only feedbackmode for the aperiodic PUSCH-based reporting mode may include mode 1-0.For example, for a DL CC or serving cell, the WTRU 102 may calculate awideband CQI value assuming transmission on the entire bandwidth of thatCC or serving cell. The WTRU 102 may report the calculated CQI values(e.g., one CQI value per CC or serving cell) for DL CCs or serving cellsconfigured by higher layer for which the aperiodic reports are required.A wideband CQI value may represent channel quality for the firstcodeword of the corresponding CC or serving cell, even when the RankIndication (RI) for that CC or serving cell may be greater than one.

Transmission modes that may support the wideband CQI-only feedback modefor the aperiodic PUSCH-based reporting mode may include, but notlimited to, transmission mode 1 such as single-antenna port,transmission mode 2 such as transmit diversity, transmission mode 3 suchas open-loop spatial multiplexing, and/or transmission mode 7 such asWTRU-specific reference signals.

Table 2 shows an example field and a corresponding bit width for the CQIfeedback using wideband reports for PDSCH transmissions associated withmultiple DL CCs or serving cells according to Mode 1-0. N_(CC) in Table2 may denote the number of DL CCs or serving cells. As shown in Table 2,the bit width may be 4 DL CCs or serving cells for the CQI feedbackusing wideband reports for PDSCH transmissions associated with multipleDL CCs or serving cells according to Mode 1-0 for transmission modes 1,2, 3 and 7. The number of DL CCs or serving cells may be configured bydedicated signaling for which the WTRU 102 may transmit an aperiodicfeedback report.

TABLE 2 Field for channel quality information (CQI) feedback based onMode 1-0 for transmission modes 1, 2, 3 and 7 Field Bit width Wide-bandCQI codeword 4N_(CC)

In an embodiment, a transmission mode may be used to transmit a combinedwideband CQI and wideband PMI feedback for the aperiodic PUSCH-basedreporting for carrier aggregation. For example, Mode 1-1 may beconfigured to support the combined reporting. For example, for a DL CCor serving cell, the WTRU 102 may select a single precoding matrix fromthe codebook subset. For a DL CC or serving cell, the WTRU 102 maycalculate a wideband CQI value per codeword assuming the use of thecorresponding selected precoding matrix, and transmission on the entirebandwidth of that CC or serving cell. The WTRU 102 may report thecalculated CQI values for DL CCs or serving cells configured by higherlayer for which the aperiodic reports that may be required. For example,one CQI may be reported per CC or serving cell. The WTRU 102 may reportthe selected PMI for DL CCs or serving cells configured by higher layerfor which the aperiodic reports that may be required. For example, onePMI may be reported per CC or serving cell.

In an embodiment, the combined wideband CQI and wideband PMI reportingmode such as Mode 1-1 may be supported on PUSCH. For example,transmission modes that may support Mode 1-1 may include transmissionmode 4 for closed-loop spatial multiplexing, and/or transmission mode 6for closed-loop Rank-1 precoding.

Table 3 shows example fields and corresponding bit widths for the CQIfeedback for wideband reports for PDSCH transmissions associated withmultiple DL CCs or serving cells according to Mode 1-1.

TABLE 3 Fields for channel quality information (CQI) feedback based onMode 1-1 for transmission modes 4 and 6 Bit width 2 antenna ports 4antenna ports Field Rank = 1 Rank = 2 Rank = 1 Rank > 1 Wide-band 4N_(CC) 4 N_(CC) 4 N_(CC) 4 N_(CC) CQI codeword 0 Wide-band 0 4 N_(CC) 04 N_(CC) CQI codeword 1 Wide-band 2 N_(CC) N_(CC) 4 N_(CC) 4 N_(CC) PMI

In an embodiment, a wideband spatial differential CQI approach may beapplied to the second codeword in one or more CCs or serving cells forPUSCH-based reporting. This approach may optimize the aperiodic feedbackoverhead using carrier aggregation with CQI Feedback Mode 1-1 andTransmission Mode 4. The wideband CQI value for the second codewordcorresponding to the PDSCH transmission on a given DL CC or serving cellmay be encoded differentially with respect to the CQI of the firstcodeword using N-bits, where N may be 3.

Table 4 shows example fields and corresponding bit widths for CQIfeedback for wideband reports according to Mode 1-1 with a widebandspatial differential CQI.

TABLE 4 Fields for channel quality information (CQI) feedback based onMode 1-1 using a wideband spatial differential CQI scheme Bit width 2antenna ports 4 antenna ports Field Rank = 1 Rank = 2 Rank = 1 Rank > 1Wide-band 4 N_(CC) 4 N_(CC) 4 N_(CC) 4 N_(CC) CQI codeword 0 Wide-bandCQI 0 3 N_(CC) 0 3 N_(CC) codeword 1 Precoding 2 N_(CC) N_(CC) 4 N_(CC)4 N_(CC) matrix indication

Table 5 shows example CQI and PMI feedback types for aperiodic reportingon PUSCH according to Mode 1-1.

TABLE 5 CQI and PMI Feedback Types for aperiodic reporting on PUSCH PMIFeedback Type No PMI Single PMI Multiple PMI PUSCH CQI Wideband Mode 1-0Mode 1-1 Mode 1-2 Feedback (wideband Type CQI) WTRU Mode 2-0 Mode 2-2Selected (subband CQI) Higher Layer- Mode 3-0 Mode 3-1 configured(subband CQI)

In carrier aggregation, a reporting mode may include CQI values for twoor mode DL CCs or serving cells. For example, there may be two DL CCs orserving cells, a primary carrier such as Pcell, and a secondary carrysuch as Scell. The codeword index may be computed. For example, the aM-bit wideband spatial differential CQI value for codeword 0 of theprimary carrier (C₀P), and codeword 0 of the secondary carrier (C₀S),and codeword 1 of the primary carrier (C₁P), may be computed as follows.If the primary carrier has two codewords and the secondary carrier hasone codeword then,

${C_{1}P\mspace{14mu}{carrier}\mspace{14mu}{offset}\mspace{14mu}{level}} = {\left\lceil \frac{\begin{matrix}\left( {\left( {{wideband}\mspace{14mu}{CQI}\mspace{14mu}{index}\mspace{14mu}{for}\mspace{14mu} C_{o}P} \right) +} \right. \\\left. \left( {{wideband}\mspace{14mu}{CQI}\mspace{14mu}{index}\mspace{14mu}{for}\mspace{14mu} C_{0}S} \right) \right)\end{matrix}}{2} \right\rceil - {{wideband}\mspace{14mu}{CQI}\mspace{20mu}{index}\mspace{14mu}{for}\mspace{14mu} C_{1}P}}$If both the primary carrier and secondary carrier has two codewordsthen,

${C_{1}P\mspace{14mu}{carrier}\mspace{14mu}{offset}\mspace{14mu}{level}} = {\left\lceil \frac{\begin{matrix}\left( {\left( {{wideband}\mspace{14mu}{CQI}\mspace{14mu}{index}\mspace{14mu}{for}\mspace{14mu} C_{o}P} \right) +} \right. \\\left. \left( {{wideband}\mspace{14mu}{CQI}\mspace{20mu}{index}\mspace{14mu}{for}\mspace{20mu} C_{0}S} \right) \right)\end{matrix}}{2} \right\rceil - \left\lceil \frac{\begin{matrix}\left( {\left( {{wideband}\mspace{14mu}{CQI}\mspace{14mu}{index}\mspace{14mu}{for}\mspace{14mu} C_{1}P} \right) +} \right. \\\left. \left( {{wideband}\mspace{14mu}{CQI}\mspace{14mu}{index}\mspace{14mu}{for}\mspace{14mu} C_{1}S} \right) \right)\end{matrix}}{2} \right\rceil}$The computation described above may be generalized to a primary carrierand two or more secondary carriers.

A mapping of the offset value to a differential CQI value may be derivedfrom a table lookup an example of which is provided in Table 6 below,

TABLE 6 Mapping of spatial differential CQI value to offset valueSpatial differential CQI value Offset level 0 0 1 1 2 2 3 3 . . . . . .J ≥J K ≤−K . . . . . . 5 −3  6 −2  7 −1 In an embodiment, there may be more than one mapping table for variouscombinations of DL serving cells, transmission modes, or the mappingcould be derived using a suitable formulae.

In one embodiment, the WTRU 102 may be configured with at least oneuplink resource allocation for the transmission of CSI reports only. Forexample, upper layers such as RRC may configure the resource allocationvia a semi-persistent uplink grant (hereafter a SPS-CSI grant). Forexample, the WTRU 102 may be allocated a dedicated resource for a PUSCHtransmission such that the resource may be available for CSItransmission periodically. For example, the WTRU 102 may be allocated adedicated resource for a PUSCH transmission such that dynamic schedulingusing PDCCH may not be necessary for the WTRU 102 to perform the PUSCHtransmission for CSI information.

The WTRU 102 may be configured with a SPS-CSI grant for at least oneserving cell. For example, the configured SPS-CSI grant may beapplicable to a transmission on the primary cell (PCell). For example,the configured SPS-CSI may be applicable to a transmission on aconfigured secondary cell (SCell). In an embodiment, the WTRU 102 may beconfigured with a plurality of SPS-CSI grants, for example, on the sameserving cell (e.g. on the PCell), on the PCell and one or more SCells,or on multiple SCells. For example, the WTRU 102 may be granted withperiodically reoccurring uplink transmission resources using one or moreresource blocks (RBs) on the PUSCH of the PCell. The period for CSIreporting may equal to or be a multiple of the periodic of theconfigured grant(s) for CSI transmission. In a subframe for which theWTRU 102 has a valid SPS-CSI grant and for which a CSI report should betransmitted, the WTRU 102 may transmit the CSI report based on theSPS-CSI grant.

In an embodiment, the WTRU 102 may transmit CSI reports for subframesduring Discontinuous Reception (DRX) active time. DRX is a function oroperation mode that may allow the WTRU 102 to discontinuously monitorthe PDCCH. For example, when DRX is configured, the WTRU 102 may monitorPDCCH during the DRX active time. The WTRU 102 may transmit CSI reportsfor subframes for which the WTRU 102 may monitor the PDCCH for otherdynamic grants and/or assignments for the serving cell specified in theSPS-CSI grant. In an embodiment, the WTRU 102 may not transmit CSI forsubframes that may not correspond to the DRX active time. For example,when DRX is configured and the WTRU 102 is not in DRX active time theWTRU 102 may not transmit SRS and may not report CQI/PMI/RI on thePUCCH.

The WTRU 102 may receive a configuration for the SPS-CSI grant by layer3 signaling such as RRC. The WTRU 102 may start using the configuredgrant for CSI as soon as the grant is received, or after apre-determined delay, or after subsequent control signaling is receivedthat may activate the SPS-CSI grant and/or the CSI reporting. Forexample, the WTRU 102 may use the configured SPS-CSI grant when the WTRU102 has a valid configuration for periodic CSI reporting. For example,the WTRU 102 may use the configured SPS-CSI grant once the SPS-CSI grantis activated, once the CSI reporting is activated, when in DRX activetime if DRX is configured, and/or if there is at least one SCellactivated.

The WTRU 102 may determine that the WTRU 102 may use or activate theconfigured SPS-CSI grant based on an indication from the reception oflayer 1 signaling. For example, the WTRU 102 may use or activate theconfigured SPS-CSI grant based on a DCI scrambled with a specific RNTI.For example, the WTRU 102 may use or activate the configured SPS-CSIgrant based on a DCI including an explicit indication that periodic CSIshould be reported using the configured grant for CSI, if the DCIreception timing coincides with the subframe for which the configuredgrant would be applicable if activated. For example, the WTRU 102 mayuse or activate the configured SPS-CSI grant based on a DCI, if thetiming of the transmission that corresponds to the grant received in theDCI would coincide with a subframe for which the configured grant forCSI transmission would be applicable if activated. In an embodiment, theindication is conveyed using the aperiodic CSI request bit in said DCI.

The WTRU 102 may determine that the WTRU 102 may use or activate theconfigured SPS-CSI grant from the reception of layer 2 signaling. Forexample, a MAC control element may be used to indicate that the grantmay be activated. The WTRU 102 may determine that the WTRU 102 may stopusing, such as deactivate the configured SPS-CSI grant from thereception of layer 1 control signaling or layer 2 control signalingsimilar to the control signaling described for the activation process.

In an embodiment, the WTRU 102 may determine that the WTRU 102 may stopusing, such as deactivate the configured SPS-CSI grant, when the WTRU102 determines that the radio link quality of either a primary cell(PCell) and/or the serving cell for which the configured SPS-CSI grantis applicable is below a certain threshold. For example, the WTRU 102may stop using, such as deactivate the configured SPS-CSI grant, basedon a determination that the downlink carrier used as the pathlossreference for the uplink carrier for which the configured SPS-CSI grantis applicable experiences physical layer problems and/or radio linkfailure. For example, the WTRU 102 may stop using, such as deactivatethe configured SPS-CSI grant, based on a determination that the uplinkcarrier for which the configured SPS-CSI grant is applicable experiencesphysical layer problems and/or radio link failure such as following oneor more failure to successfully complete the random access procedure. Inan embodiment, the WTRU 102 may determine that the WTRU 102 may stopusing, such as deactivate the configured SPS-CSI grant when the timealignment timer (TAT) applicable to the serving cell for which theSPS-CSI grant is applicable expires. The WTRU 102 may transmit HARQ A/Nfor the activation and/or deactivation control signaling.

The WTRU 102 may refrain from transmitting the CSI report on theconfigured grant for CSI if dynamic control signaling (e.g. PDCCH) isreceived. For example, the dynamic control signaling may grant uplinktransmission resources in the same subframe and on the PUSCH of theserving cell for which the configured SPS-CSI grant also applies. TheWRTU may drop the CSI report and transmit data on the dynamicallyscheduled uplink resources. The WRTU may transmit the CSI report or aportion of the CSI report on a different resource than the configuredSPS-CSI resources, e.g. on the PUCCH or on a different PUSCHtransmission including the transmission that would have other collidedwith the SPS-CSI grant.

In an embodiment, HARQ ACK/NACK report and CQI/PMI/RI report may betransmitted separately. Separate transmission of ACK/NACK on PUCCH andCQI on PUSCH may be used when there are not enough resources availablein PUSCH to accommodate both ACK/NACK and CQI. For example, when aCQI/PMI/RI report and ACK/NACK coincide in a subframe, the HARQ ACK/NACKmay be transmitted on PUCCH. Resources next to the reference symbols onthe PUSCH that may be reserved for ACK/NACK signaling may be freed up. Alarger channel status report may be transmitted on PUSCH at a reportinginstance. CQI/PMI/RI may be transmitted on PUSCH.

FIG. 6 shows an example mapping of CQI/PMI, RI and data onto PUSCH. Asshown, CQI/PMI, RI, and data may be multiplexed onto PUSCH. As shown inFIG. 6, PUSCH RS 610, CQI/PMI 620, RI 630 and data 640 may betransmitted in RBs 605 over slot 0 660 and slot 1 670. As shown, RI 630may be transmitted on the resources next to the PUSCH RS 610 on thePUSCH. The resources next to the PUSCH RS 610 may be reliable resourceswithin a slot, as the channel estimates are of better quality.Therefore, by mapping the RI 630 on these resources, a lower coding ratemay be used for RI signaling. This way, the overall control signalingoverhead on PUSCH may be reduced.

FIG. 16 shows an example method for transmitting a CSI report. Forexample, at 1810, an indication for transmitting a CSI report may bereceived. The CSI report may be a periodic report or an aperiodicreport. According to the indication, a HARQ ACK/NACK report and a CQIreport may coincide in a subframe. At 1820, an indication on whethersimultaneous transmission of ACK/NACK and CQI on PUSCH is allowed may bereceived. For example, a parameter such as simultaneousAckNackAndC

IPUSCH may be provided by higher layers. For example, when the parametersimultaneousAckNackAndCQIPUSCH is set TRUE, the CQI/PMI/RI may beallowed to simultaneously transmit HARQ ACK/NACK and CQI in the samesubframe on PUSCH, and when the parameter simultaneousAckNackAndCQIPUSCHis set FALSE, the WTRU 102 may not be allowed to simultaneously transmitHARQ ACK/NACK and CQI in the same subframe on PUSCH. If it is determinedthat simultaneous transmission of HARQ ACK/NACK and CQI/PMI/RI isallowed at 1830, at 1840, HARQ ACK/NACK may be multiplexed withCQI/PMI/RI, and be transmitted on PUSCH. If it is determined thatsimultaneous transmission of HARQ ACK/NACK and CQI/PMI/RI is not allowedat 1830, at 1850, HARQ ACK/NACK may be transmitted on PUCCH, andCQI/PMI/RI may be transmitted on PUSCH. In another embodiment, if it isdetermined that simultaneous transmission of HARQ ACK/NACK andCQI/PMI/RI is not allowed at 1830, HARQ ACK/NACK may be transmitted onPUCCH, and CQI/PMI/RI report may be dropped.

Separate transmission of HARQ ACK/NACK on PUCCH and CQI/PMI/RI on PUSCHmay be configured by higher layer signaling. For example, the parametersimultaneousAckNackAndCQIPUSCH may be defined for periodic CQI reportand/or aperiodic CQI reporting. For example, the parametersimultaneousAckNackAndCQIPUSCH may be included in IE CQI-ReportConfig asfollows:

CQI-ReportConfig_R10 ::= SEQUENCE { cqi-ReportModeAperiodic ENUMERATED {rm12, rm20, rm22, rm30, rm31, spare3, spare2, spare1} OPTIONAL, -- NeedOR nomPDSCH-RS-EPRE-Offset INTEGER (−1..6), simultaneousAckNackAndCQIPUSCH BOOLEAN cqi-ReportPeriodicCQI-ReportPeriodic OPTIONAL -- Need ON } CQI-ReportPeriodic ::= CHOICE {release NULL, setup SEQUENCE { cqi-PUCCH-ResourceIndex INTEGER (0..1185), cqi-pmi-ConfigIndex INTEGER (0..1023),cqi-FormatIndicatorPeriodic CHOICE { widebandCQI NULL, subbandCQISEQUENCE { k INTEGER (1..4) } }, ri-ConfigIndex INTEGER (0..1023)OPTIONAL, -- Need OR  simultaneousAckNackAndCQI BOOLEAN } }

In an embodiment, opportunistic transmission of CSI for multiplecarriers may be used when PUCCH and PUSCH are transmitted in samesub-frame. For example, the WTRU 102 may report CSI for a first carrieron PUSCH in a sub-frame, if a grant for transmitting PUSCH exists inthis subframe and if CSI for a second carrier is reported on PUCCH inthe same sub-frame. The first and the second carriers may be differentcarriers. In an embodiment, the CSI for the second carrier may not bereported on PUCCH until Na sub-frames after the present or currentsubframe. For example, the WTRU 102 may report CSI for a carrier onPUSCH in a sub-frame, if an UL grant to transmit on PUSCH may exist inthe sub-frame. In another embodiment, the WTRU 102 may report CSI for acarrier on PUSCH in a sub-frame, if CSI for the carrier has not beenreported within the last predetermined Nb subframes, for example, onPUCCH only, PUSCH only, or on either PUCCH or PUSCH.

FIG. 7 illustrates example opportunistic transmission of CSI formultiple carriers. As shown in FIG. 7, the WTRU 102 may operate withmultiple carriers such as three carriers. The WTRU 102 may be configuredto transmit periodic CSI reports on PUCCH, with cycling between thecarriers. As shown, CSI reports for carrier 1 710, CSI reports forcarrier 2 720, CSI reports for carrier 3 730 may be transmittedperiodically, one carrier at a time, with cycling in between. Thetransmission of a CSI report for a single carrier at a time in a PUCCHsubframe may help the network to avoid over-allocating PUCCH resourcesfor CSI reporting. Because CSI is reported less frequently for a givencarrier, there may be a latency issue for the CSI if multiple downlinkcarriers needed to be utilized. Opportunistic transmission of CSI mayenable the network to accelerate the reporting of CSI for these carriersby providing an UL grant to the WTRU, without incurring the cost of afull aperiodic CQI report.

According to an embodiment, the HARQ ACK/NACK information bits and theCSI bits may be jointly encoded prior to scrambling and modulation andbe transmitted on a PUCCH subframe. The payload sizes for the HARQACK/NACK and the CSI transmissions may be different. The channel codingrate may vary based on the number of activated or configured DL CCsand/or transmission modes for which HARQ feedback or periodic CSI are tobe transmitted.

For example, the channel encoder may be a block coding-type scheme suchas punctured (64, k) Reed-Muller (RM) code for a DFT-S-OFDM based orsimilar structure with SF=5 or punctured (128, k) Reed-Muller code forDFT-S-OFDM based structure with SF=3.

For example, when SF=5, a (48, A) block code may be derived from apunctured RM(64,k) and/or a cyclically repeated RM(32,k). The block codemay be used where A is the payload size of the UCI. The codewords of RMmay be a linear combination of the N basis sequences denoted M_(i,n),where N may be the maximum number of PUCCH payload bits. Depending onwhether discontinuous transmission (DTX) may be signaled for a DL CC,the value of N may be, for example, between 10-12 bits or the like, forthe maximum number of aggregated CCs. For example, the maximum number ofaggregated CCs may be 5 DL CCs. The encoded bit sequence of length 48 atthe output of the channel encoder may be denoted by b₀, b₁, . . . , b₄₇where

$b_{i} = {\sum\limits_{n = 0}^{A - 1}\;{a_{n} \cdot M_{i,n}}}$i = 0, 1, …  , 47with a₀, a₁, . . . a_(A−1) as the input bits to the channel encoder.

Both addition and multiplication operations in the above formula may beperformed in vector-space domain, for example, 1·1=1, 0·1=0, 1·0=0,0·0=0, 1+1=0, 0+1=1, 1+0=1, 0+0=0.

Joint coding may be applied across both slots of a PUCCH subframe. Jointcoding across both slots may maximize the maximum achievable frequencydiversity gain for UCI transmissions on PUCCH. Joint coding may beapplied across a single slot. For example, an RM(32,k) encoded sequencemay be repeated on both slots for SF=5. For example, an RM(64,k) encodedsequence may be repeated on both slots for SF=3.

In the case of joint coding using a rate-matched RM (32, k) across asubframe, basis sequences may be defined to support joint channelcoding. The total payload size of CSI and HARQ ACK/NACK may exceed 11bits. The payload size of CQI in Rel-8 may vary from one to 11 bitswhile the payload size of HARQ ACK/NACK in Rel-10 or later releases mayvary from 1 to 11 bits. In an embodiment, the 11 basis sequencesprovided in Rel-8 specification for RM (32, k) may be extended bydefining additional basis sequences. These newly introduced basissequences may be derived from the Reed-Muller encoding matrix used forforming other previously defined basis sequences. Applicableinterleaving function that has been applied on the legacy Rel-8 basissequences may be applied to the extended basis sequences. For example,to support up to 13 bits of payload, two additional basis sequences maybe defined and augmented in accordance with Table 7.

TABLE 7 The extended basis sequences for RM (32, k) code. i M_(i, 0)M_(i, 1) M_(i, 2) M_(i, 3) M_(i, 4) M_(i, 5) M_(i, 6) M_(i, 7) M_(i, 8)M_(i, 9) M_(i, 10) M_(i, 11) M_(i, 12) 0 1 1 0 0 0 0 0 0 0 0 1 X X 1 1 11 0 0 0 0 0 0 1 1 X X 2 1 0 0 1 0 0 1 0 1 1 1 X X 3 1 0 1 1 0 0 0 0 1 01 X X 4 1 1 1 1 0 0 0 1 0 0 1 X X 5 1 1 0 0 1 0 1 1 1 0 1 X X 6 1 0 1 01 0 1 0 1 1 1 X X 7 1 0 0 1 1 0 0 1 1 0 1 X X 8 1 1 0 1 1 0 0 1 0 1 1 XX 9 1 0 1 1 1 0 1 0 0 1 1 X X 10 1 0 1 0 0 1 1 1 0 1 1 X X 11 1 1 1 0 01 1 0 1 0 1 X X 12 1 0 0 1 0 1 0 1 1 1 1 X X 13 1 1 0 1 0 1 0 1 0 1 1 XX 14 1 0 0 0 1 1 0 1 0 0 1 X X 15 1 1 0 0 1 1 1 1 0 1 1 X X 16 1 1 1 0 11 1 0 0 1 0 X X 17 1 0 0 1 1 1 0 0 1 0 0 X X 18 1 1 0 1 1 1 1 1 0 0 0 XX 19 1 0 0 0 0 1 1 0 0 0 0 X X 20 1 0 1 0 0 0 1 0 0 0 1 X X 21 1 1 0 1 00 0 0 0 1 1 X X 22 1 0 0 0 1 0 0 1 1 0 1 X X 23 1 1 1 0 1 0 0 0 1 1 1 XX 24 1 1 1 1 1 0 1 1 1 1 0 X X 25 1 1 0 0 0 1 1 1 0 0 1 x x 26 1 0 1 1 01 0 0 1 1 0 X X 27 1 1 1 1 0 1 0 1 1 1 0 X X 28 1 0 1 0 1 1 1 0 1 0 0 XX 29 1 0 1 1 1 1 1 1 1 0 0 X X 30 1 1 1 1 1 1 1 1 1 1 1 X X 31 1 0 0 0 00 0 0 0 0 0 X X

According to an embodiment, HARQ ACK/NACK information bits and CSI bitsmay be separately encoded. For example, the HARQ ACK/NACK informationbits and the CSI bits may be encoded using a different variable codingrate prior to scrambling and modulation and be transmitted on both slotsof a PUCCH subframe. The HARQ ACK/NACK information bits and the CSI bitsmay be separately encoded such that the performance of various controlssignaling may be kept at their respective target levels. The coding rateof each individual channel encoder may be adjusted based on the desiredbit error rate (BER) or block error rate (BLER) operation point for agiven control feedback type, when the payload sizes for the HARQACK/NACK and the CSI transmissions may be different. The payload sizesfor the HARQ ACK/NACK and the CSI transmissions may be different basedon the number of activated or configured DL CCs and/or transmissionmodes for which HARQ feedback or periodic CSI are to be transmitted.

For example, when the payload size is relative small, such as 2 bits,the channel encoder may include a block coding-type scheme. The blockcoding-type scheme may include simplex code with a circular ratematching into 48 or 96 coded bits depending on the spreading factor usedfor the DFT-S-OFDM based or similar structure. The channel encoder maybe a tail-biting convolutional code that may generates 48 and 96 codedbits at output for the DFT-S-OFDM based structures with SF=5 and SF=3,respectively.

For example, an n-bit Cyclic Redundancy Check (CRC) may be computedbased on control information and attached to the feedback informationbits prior to the channel coding for improving error detection. The CRCmay be of a variable size that may be adjusted based on the payload sizeof UCI or the type of control signaling such as HARQ ACK/NACK or CSI. Anon-limiting example of the CRC length may be 8 bits that may achieve amiss detection rate of 0.4%. The CRC may lower the probability of falsealarm at the eNodeB and therefore the performance target on Pr(DTX->ACK)may be relaxed. In an embodiment, the CRC may be indicative of theactual payload size used by the WTRU 102 prior to encoding, and/or theidentity or number of the configured or activated DL CCs on which theWTRU 102 receives the DL assignment. Thus, the performance of detectormay be improved when the WTRU 102 misses detecting the downlinkassignment from the eNB on one or multiple DL CCs.

FIG. 8 illustrates a non-limiting exemplary PUCCH encoding chain for aDFT-S-OFDM based PUCCH transmission. As shown, the UCI data 805 to befed back by the WTRU 102 may enter a coding unit. At 810, CRC paritybits may be calculated using UCI data 805. For example, the entire blockmay be used to calculate CRC parity bits. For example, the WTRU 102 mayappend the CRC bits to the UCI bits. At 820, the CRC bit sequence may bemasked by identity or number of activated or configured DL CCs 830 onwhich the WTRU 102 may receive DL assignment. At 840, tail-bitingconvolutional encoding may be performed. For example, the WTRU 102 mayapply a rate ⅓ tail-biting convolutional coding on the input bits. At850, the coded bits may be fed to a rate matching block.

In an embodiment, the HARQ ACK/NACK information bits may be encodedusing a sub-coder prior to joint coding with the CSI bits as shown inFIG. 9. As shown, HARQ ACK/NACK bit sequence 910 may be encoded viaACK/NACK sub-encoder 920. The encoded ACK/NACK bit sequence may bejointly encoded with CSI bit sequence 940 via Reed-Muller encoder 930 toproduce output bit sequence 950.

For example, when ACK/NACK payload sizes are small, e.g., 3, 4 bits, orthe like, the ACK/NACK sub-encoder of the WTRU 102 may include a simplexcode and/or repetition code. When ACK/NACK payload sizes are large,e.g., 5 to 11 bits, the ACK/NACK sub-encoder of the WTRU 102 may be aReed-Muller code.

In an embodiment, the sequence of ACK/NACK bits a₀″, a₁″, a₂″, . . . ,a″_(N) _(A/N) ⁻¹ may first be encoded by the WTRU 102 using aReed-Muller code such as RM(20, N_(A/N)) as follows:

$a_{i} = {\sum\limits_{n = 0}^{N_{A/N} - 1}\;{a_{n}^{''} \cdot M_{i,n}}}$i = 0, 1, …  , A^(″) − 1where N_(A/N)∈{1, 2, . . . 11} may be the number of ACK/NACK bitsfeedback and A″=20. The encoded ACK/NACK bit sequence a₀, a₁, . . . ,a_(A″) may then be multiplexed with the CSI bit sequence of the WTRU 102denoted by a₀′, a₁′, a₂′, a₃′, . . . , a′_(A′−1) to yield the sequencea₀, a₁, a₂, a₃, . . . , a_(A−1) as follows:

a_(A″+i)=a_(i)′, i=0, . . . , A′−1. The sequence a₀, a₁, a₂, a₃, . . . ,a_(A−1) may be encoded using a Reed-Muller code such as RM(48, A) toyield the output bit sequence b₀, b₁, b₂, b₃, . . . , b_(B−1) asfollows:

$b_{i} = {\sum\limits_{n = 0}^{N_{A} - 1}\;{a_{n} \cdot M_{i,n}}}$i = 0, 1, …  , B − 1where B=48 for DFT-S-OFDM based PUCCH with spreading factor of five.

In an embodiment, the HARQ ACK/NACK encoded bits may be appended to theCSI bit sequence of the WTRU 102 prior to Reed-Muller encoding asillustrated in FIG. 10. As shown, the input orders of sub-coded ACK/NACKand CSI bit sequences may be exchanged to improve DTX handling at eNB.As shown in FIG. 10, ACK/NACK bit sequence 1020 may be encoded viaACK/NACK sub-encoder 1030. The encoded ACK/NACK bit sequence may bejointly encoded with CSI bit sequence 1010 via Reed-Muller encoder 1040to produce output bit sequence 1050. A DTX situation may relate to thefailure of the WTRU 102 to detect the DL resource allocation grant in agiven subframe. The eNB may detect the CSI information bits of the WTRU102 irrespective of whether ACK/NACK information bits are present.

In an embodiment, the encoded HARQ ACK/NACK bits of the WTRU 102 may bepunctured into the encoded CSI bit sequence as shown in FIG. 11. Asshown, ACK/NACK bit sequence 1110 may be encoded via ACK/NACKsub-encoder 1120. CSI bit sequence 1130 may be encoded via Reed-Mullerencoder 1140. The encoded CSI bit sequence may be fed into a ratematching module 1150. The encoded ACK/NACK bit sequence may be puncturedinto the CSI bit sequence via a multiplexing/puncturing module, toproduce output sequence 1170.

The CSI bit sequence of the WTRU 102 may be encoded and rate matched tooccupy the resources within a PUCCH RB, e.g., 48 bits. The non-puncturedbits may be unaffected by the absence of the HARQ ACK/NACK bits of theWTRU 102 where the WTRU 102 may have missed the DL schedulingassignment, such as DTX.

For example, the channel quality bits input to the channel coding blockof the WTRU 102 denoted by a₀′, a₁′, a₂′, a₃′, . . . , a′_(A′−1) mayfirst encoded using an RM(32, A′). The output bit sequence b₀, b₁, b₂, .. . , b_(B−1) with B=48 may be obtained by circular repetition of thesequence

,

,

, . . . ,

as follows:b _(i)=

where i=0, 1, 2, . . . , B−1.

In an embodiment, the sequence of ACK/NACK bits a₀″, a₁″, a₂″, . . . ,a″_(N) _(A/N) ⁻¹ may be separately encoded to result in b₀′, b₁′, b₂′,b₃′, . . . , b′_(B′−1) where B′ is the length of the encoded ACK/NACKsequence. For example, the encoded ACK/NACK sequence may be puncturedinto the encoded CSI sequence as follows:b _(i) =b _(i) ′,i=0, . . . ,B′−1.

In an embodiment, physical resources may be mapped in DFT-S-OFDM PUCCH.For example, the WTRU 102 may employ a channel interleaver for uplinkcontrol information transmissions. The achievable frequency diversitygain may be thus maximized.

For example, the channel interleaving can be performed at the bit-levelon the encoded bit sequence or on the scrambled bit sequence such thatbits may be written to a rectangular matrix row-by-row and read outcolumn-by-column. For example, bit sequence may be written to a 24 by 2matrix for SF=5, or a 48 by 2 matrix for SF=3. In an embodiment,adjacent control bits may be mapped across the two slots.

For example, the channel interleaving may be applied on the symbol-levelwhere adjacent uplink control information modulated symbols may bemapped first in the time domain across the two slots within a subframe,and then in the frequency-domain across the subcarriers within eachslot. For example, even QPSK symbols may be transmitted on the evenslots and odd QPSK symbols mapped on the odd slots.

In an embodiment, CSI and HARQ symbols may be multiplexed into PUCCHresource. For example, symbols may be multiplexed into PUCCH resourcefrom CSI such as CQI, RI and/or PMI information, and HARQ ACK/NACKinformation, when separate coding and interleaving may applied on thedifferent types of information.

For example, corresponding resources may be applied within a single RB.For example, dimensioning of the corresponding resources with respect tothe ACK/NACK and/or CSI payload can be applied within a single RB suchthat channel coding gain may be improved.

In an embodiment, HARQ acknowledgements may be transmitted on PUCCH. Theavailable resources on the PUCCH may be used for ACK/NACK/DTX feedbacktransmissions. In an example, the HARQ ACK/NACK symbols may be firstmapped in the time-domain across the two slots and then across thefrequency-domain across the subcarriers. In an example, the symbols maybe first mapped in the frequency domain and second in the time domain.

In an embodiment, channel status reports may be transmitted on PUCCH.The available resources on the PUCCH may be used for CSI feedbacktransmissions. In an example, the channel status report symbols may befirst mapped in the time-domain across the two slots and then across thefrequency-domain across the subcarriers. In an example, the symbols maybe first mapped in the frequency domain and second in the time domain.

In an embodiment, HARQ ACK/NACK and channel status report may betransmitted on PUCCH. HARQ symbols and CSI symbols may be multiplexedsuch that different control signaling may be allocated a different sizeof physical resource elements. The size of the reserved resources foreach of ACK/NACK and CSI may be scaled according to the variable codingrate and/or the modulation order to for a given control signaling. TheWTRU 102 may use different offsets for mapping of various controlssignaling information. The offsets may be semi-statically, statically,or dynamically configured by higher-layer signaling. Control informationmay be mapped such that each of ACK/NACK and CSI may be present in bothslots of a subframe.

For example, HARQ ACK/NACK feedback and CSI may be multiplexed into thesame PUCCH resource. The respective number of symbols used for each typeof information may be determined. For example, HARQ ACK/NACK may beprioritized over CSI information. The number of coded symbols requiredfor HARQ ACK/NACK information, Q_(AN_PUCCH), may be determined. IfQ_(AN_PUCCH) is smaller than the maximum available in the PUCCH,Q_(MAX_PUCCH), CSI information may be multiplexed. In an example, CSIinformation may be multiplexed based on a condition that Q_(AN_PUCCH) isless than Q_(MAX_PUCCH) by a threshold value. In an embodiment, ifQ_(AN_PUCCH) equals to or is greater than Q_(MAX_PUCCH), or thedifference between Q_(AN_PUCCH) and Q_(MAX_PUCCH) is lower than athreshold value, only HARQ ACK/NACK information may be transmitted. Forexample, multiplexing HARQ ACK/NACK information and CSI may not beperformed.

In an embodiment, the mapping between Q_(AN_PUCCH) and O_(AN_PUCCH) maybe fixed and may be provided in a look-up table. In an embodiment,Q_(AN_PUCCH) may be calculated based on a function of the number of HARQinformation bits to transmit, O_(AN_PUCCH). In an embodiment,Q_(AN_PUCCH) may be calculated based on a proportionality factor,B_(PUCCH), multiplying the number of HARQ ACK/NACK information bit totransmit. Parameter(s) of the function may be predefined or provided byhigher layer. The proportionality factor, B_(PUCCH), may adjust thefraction of the PUCCH energy available to HARQ ACK/NACK information. Inan embodiment, Q_(AN_PUCCH) may be calculated based on the maximumnumber of symbols, Q_(MAX_PUCCH), that may be available for HARQACK/NACK information, and/or CSI information in a DFT-S-OFDM based PUCCHtransmission. The number of symbols may be different based on whetherextended or normal prefix is used.

The number of symbols Q_(AN_PUCCH) used for HARQ ACK/NACK informationmay correspond to the lower value between Q_(MAX_PUCCH) and f(O_(AN_PUCCH)×B_(PUCCH)), where the function f ( ) may provide thelargest possible number of symbols for HARQ ACK/NACK information thatmay be smaller than the argument. In an embodiment, the function f ( )may provide the smallest possible number of symbols for HARQ ACK/NACKinformation that may be larger than the argument. The function f( ) maybe defined such that a correct number of symbols may be allocated, giventhat the granularity of the number of symbols that may be used in aPUCCH may be larger than 1.

In an embodiment, the number of symbols available to CSI information,Q_(CSI_PUCCH), may be determined. For example, Q_(CSI_PUCCH) may becomputed by comparing the number of symbols used for HARQ ACK/NACKinformation, Q_(AN_PUCCH), and the maximum number of symbolsQ_(MAX_PUCCH). The number of symbols available to CSI informationQ_(CSI_PUCCH) may include the difference between Q_(MAX_PUCCH) andQ_(AN_PUCCH). In an embodiment, there may be a minimum amount of symbolsavailable to CSI information such that HARQ ACK/NACK information and CSImay be multiplexed. In an embodiment, the CSI information may be droppedwhen the amount of symbols available to CSI information is below athreshold value.

The type of CSI information and/or the number of DL serving cells beingreported may be determined based on the number of available symbols forCSI. For instance, if Q_(CSI_PUCCH) is below a threshold value, onlyrank information (RI) for a single DL serving cell may be reported.

In an embodiment, the amount of CSI information that may be reported maybe determined based on a maximum coding rate for CSI information. Themaximum coding rate may be dependent on the type of CSI. For example,the maximum coding rate for RI may be lower than for other type of CSIwith higher robustness requirement. For instance, the maximum number ofinformation bits available for CSI, O_(CSI_PUCCH), may be calculatedbased on a maximum coding rate and number of available coded bits. In anembodiment, O_(CSI_PUCCH) may be the product between a maximum codingrate and number of available coded bits, rounded down or up to theclosest integer or to the closest integer matching a possible number ofCSI information bits. A ratio K between the number of coded bits and thenumber of symbols may correspond to the number of bits per modulationsymbol divided by the spreading factor SF. The embodiments describedabove with respect to multiplexing HARQ ACK/NACK information with CSImay be used for the multiplexing of different types of CSI in the samesubframe. For instance, RI may be multiplexed with CQI/PMI.

FIG. 12 illustrates a non-limiting exemplary control signal mapping fora DFT-S-OFDM based PUCCH transmission. As shown, CSI resources 1240 maybe placed at the beginning of RB 1210 and be mapped sequentially to thetwo slots on one subcarrier of slot 0 1220 before continuing on the nextsubcarrier until all resources allocated for CSI transmission arefilled. HARQ ACK/NACK symbols 1250, on the other hand, may be placed atthe end of RB 1210. In other words, CSI 1240 may be frequencymultiplexed with HARQ ACK/NACK 1250 on the PUCCH.

According to an embodiment, the CSI transmitted on PUCCH may use thesame modulation scheme as the HARQ acknowledgements. Alternatively, CSIand HARQ control signaling may be performed using different modulationschemes. For example, HARQ ACK/NACK may be modulated using QPSKmodulation, and CSI may be modulated using higher order modulations suchas QAM16 or QAM64.

Various multiplexing methods may be used. The HARQ ACK/NACK symbols maybe placed at both extremities of the RB frequency-wise. This may beperformed within each slot, or the symbols may be placed at oneextremity for the first slot and at the other extremity for the secondslot. Such an arrangement may maximize frequency diversity for the HARQACK/NACK symbols. The above-described arrangement may be used for CSIsymbols. In another embodiment, the subcarriers where HARQ ACK/NACKsymbols are placed may be positioned at equal frequency distance fromeach other. Alternatively, or in addition, the subcarriers where CSIsymbols are placed may be positioned at equal or substantially equalfrequency distance.

When CSI information is multiplexed with HARQ ACK/NACK information, theencoding of the CSI information may be performed. In an embodiment usingpuncturing, CSI information may first be encoded assuming a number ofcoded bits corresponding to the maximum number of symbols available forHARQ ACK/NACK information and CSI, Q_(MAX_PUCCH). For instance, theencoding may be using a Reed-Muller code RM(K×Q_(MAX_PUCCH),O_(CSI_PUCCH)) where K may be the ratio between the number of coded bitsand the number of symbols. The CSI coded bits may then be interleaved,modulated, spread, and positioned in available symbol locations in thePUCCH. The HARQ ACK/NACK information may also be encoded, interleaved,modulated, spread, and then positioned into a subset of the symbollocations previously utilized by CSI information, in effect puncturingthe coding of the CSI. The subset of symbols used may be determinedaccording to the embodiments of the described above.

In an embodiment, CSI information may be directly encoded assuming anumber of coded bits corresponding to the number of symbols available toCSI (Q_(CSI_PUCCH)). For instance, the encoding might be using aReed-Muller code RM(K×Q_(CSI_PUCCH), O_(CSI_PUCCH)) where K may be theratio between the number of coded bits and the number of symbols. TheCSI coded bits may then be interleaved, modulated, spread, andpositioned in symbol locations identified for CSI information. The HARQACK/NACK information may also be encoded, interleaved, modulated,spread, and then positioned into symbol locations not utilized by CSIinformation. The symbol locations for HARQ ACK/NACK information and CSImay be determined. The transmission of CSI may be prioritized on thecodeword with the highest quality metric, for example, Signal toInterference plus Noise Ratio (SINR).

The WTRUs 102 may be scheduled to share the same RB for their ULfeedback transmissions. Sharing the PUCCH resource blocks for both HARQACK/NACK and CSI transmissions may lead to lower control signallingoverhead in the system.

When CSI is multiplexed with HARQ ACK/NACK information, the transmissionpower may be adjusted as a function of at least one of, the number ofHARQ ACK/NACK bits, the number of HARQ ACK/NACK bits corresponding todetected PDCCH transmissions or semi-persistent scheduling assignments,the number of CSI bits, the number of RI bits, and/or the number ofsymbols in the PUCCH utilized for transmission of HARQ ACK/NACK, CSI,and/or RI, in case of separate coding.

More specifically, the transmission power may be based on the number ofHARQ ACK/NACK bits, or HARQ ACK/NACK bits corresponding to detectedPDCCH transmissions or semi-persistent scheduling assignments, dividedby the number or fraction of symbols of PUCCH utilized for thetransmission of this information. The transmission power may be based onthe number of CSI bits divided by the number or fraction of symbols ofPUCCH utilized for the transmission of this information. Thetransmission power may be based on the number of RI bits divided by thenumber or fraction of symbols of PUCCH utilized for the transmission ofthis information. The number or fraction of symbols of PUCCH for thetransmission of CSI or HARQ ACK/NACK may be based on the numbers of CSIand/or HARQ ACK/NACK information bits as described above.

CSI payload may be transmitted by allocating the corresponding controlregion in the uplink. In an embodiment, some of the resource blocks(RBs) that may otherwise be reserved for PUCCH transmission in UL may bereserved for a CSI structure. In case the HARQ ACK/NACK and CSI collideon the same subframe, CSI may be multiplexed with ACK/NACK.

FIG. 13 illustrates example PUCCH configuration for resource allocationon PUCCH. As shown, some of the RBs that may otherwise be reserved forPUCCH transmission in UL may be allocated for CSI structures. Forexample, the PUCCH Format 2/2a/2b 1520 from the system perspective maybe over-dimensioned, and the outermost RBs 1530 may be allocated to theCSI structures, such as PUCCH Format 3/3x. In case an HARQ ACK/NACKreport and a CQI report coincide in a subframe, PUCCH Format 3/3x can beused for concurrent transmission of CSI and HARQ ACK/NACK. As shown inFIG. 13, RBs 1540 may be resources that may be reserved for persistentPUCCH format 1/1a/1b as configured by N_(PUCCH) ⁽¹⁾ and RBs 1550 may beresources reserved for dynamic PUCCH format 1/1a/1b.

FIG. 14 illustrates example method for transmitting CSI feedback. Forexample, at 1610, the number of RBs allocated for a CSI report structuremay be received. The CSI report structure may include PUCCH Format 3/3x.The WTRU 102 may be configured by higher layer regarding the number ofRBs that may be allocated for new CSI feedback transmissions within thePUCCH control region. For example, the WTRU 102 may receive a systemparameter, such as N_(RB) ⁽³⁾, via broadcast from the system. The systemparameter may be dynamically adjusted based on the average number ofactive UEs (e.g. Re-10 or later UEs) that the system is expected tosupport. At 1630, a schedule assigned resource within the allocated RBson the PUCCH for feedback transmission using the CSI structure may bereceived. The resources used for transmission of PUCCH Format 3/3x canbe identified by a resource index such as n_(PUCCH) ⁽³⁾. This parametermay be explicitly signaled via WTRU-specific higher-layer signaling. Forexample, the scheduler may assign those RBs to Rel-10 UEs fortransmission of feedback using the CSI structures. From a Rel-8 WTRUperspective, the WTRU 102 may not be assigned any resources on theoutermost RBs by the scheduler at eNodeB. Through configuration, thisapproach may be transparent to a Rel-8 WTRU, and backward compatibilitymay be fully maintained. At 1650, CSI feedback may be transmitted on anassigned resource within the outer most allocated RBs for the CSIstructure.

One advantage of allocating the outermost RBs to the newly introducedcontrol region is that the achievable frequency diversity may bemaximized when the frequency hopping is used. This approach maycompensate for the potential loss due to the higher overhead in the newCSI carrying channel to some extent.

In an embodiment, CSI payload may be transmitted by allocating some ofthe RBs that otherwise may be reserved for PUSCH transmission in UL forCSI structure. FIG. 15 shows an example PUCCH configuration. As shown,system RBs 1710 may include RBs 1720 that may be reserved for PUCCHformat 2/2a/2b as configured by N_(RB) ⁽²⁾, RBs 1730 that may bereserved for persistent PUCCH format 1/1a/1b as configured by N_(PUCCH)⁽¹⁾, RBs 1740 that may be reserved for dynamic PUCCH format 1/1a/1b, RBs1750 that may be reserved for periodic CSI signaling on PUCCH, and RBs1760 that may be available for PUSCH. For example, the PUSCH RBs 1760next to the RBs 1740 reserved for dynamic ACK/NACK transmissions onPUCCH Format 1/1a/1b may be allocated for transmitting CSI.

From the system perspective, the scheduler may not schedule any PUSCHtransmission on these reserved RBs. This approach may be fully backwardcompatible and transparent to an earlier-versioned WTRU such as a Rel-8WTRU through proper scheduling. UEs, such as Rel-10 UEs orlater-versioned UEs, may be configured through a broadcasted systemparameter regarding the maximum number of RBs reserved for periodic CSIfeedback transmissions.

A Transmission Timing Interval (TTI) bundling scheme may be applied tothe periodic CSI feedbacks transmitted on those PUSCH RBs. The ULcoverage reliability of the new CSI structure transmitted on PUSCH maybe improved. This approach may be considered as a repetition scheme thatmay replace the HARQ process currently applied on PUSCH for datatransmission in Rel-8. Accordingly, a single periodic report may betransmitted in a set of consecutive TTIs on the same resources on PUSCH.TTI bundling may be triggered through a WTRU-specific higher layersignalling.

WTRUs, such as Rel-10 UEs or later-versioned UEs, may be configured byhigher layer regarding the number of RBs that are allocated for new CSIfeedback transmissions within the PUSCH control region. For example, abroadcasted system parameter such as N_(RB) ⁽³⁾ may be defined. Thisparameter may be dynamically adjusted based on the average number ofactive WTRUs, e.g. Re-10 or later UEs, that the system is expected tosupport. The resources used for transmission can be identified by aresource index such as n_(PUCCH) ⁽³⁾. This parameter may be explicitlysignaled via WTRU-specific higher-layer signaling.

In an embodiment, CSI payload may be extended by defining a controlregion that may include one or more RB(s). For example, a separateregion in the UL which may span over single or multiple RB(s) may beallocated for CSI with or without HARQ ACK/NACK transmissions.

CSI payload may be extended by allocating the corresponding controlregion. In an embodiment, some of the resource blocks (RBs) that mayotherwise be reserved for PUCCH transmission in UL may be reserved forCSI structure.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

What is claimed:
 1. A method for reporting channel state information(CSI), the method comprising: receiving an indication to activate asemi-persistent CSI reporting; activating the semi-persistent CSIreporting for a serving cell based on the received indication;transmitting one or more CSI reports for the serving cell, after thesemi-persistent CSI reporting is activated; determining that a timealignment timer (TAT) has expired; and deactivating the semi-persistentCSI reporting based on expiration of the TAT.
 2. The method of claim 1,wherein the received indication comprises any of: a downlink controlinformation (DCI) format, or a random access response grant.
 3. Themethod of claim 1, further comprising at least one of: determining theserving cell of a Physical Downlink Control Channel (PDCCH) on which thereceived indication is decoded; or determining the serving cellcorresponding to a Physical Downlink Shared Channel (PDSCH) on which thereceived indication is decoded.
 4. The method of claim 1, furthercomprising determining a CSI request field from the received indication,wherein the CSI request field indicates the activating or thedeactivating of the semi-persistent CSI reporting.
 5. The method ofclaim 1, wherein the one or more CSI reports are transmitted on aphysical uplink shared channel (PUSCH).
 6. The method of claim 1,wherein the one or more CSI reports are transmitted periodically.
 7. Themethod of claim 1, wherein the received indication activates thesemi-persistent CSI reporting based on downlink control information(DCI) scrambled with a Radio Network Temporary Identifier (RNTI).
 8. Themethod of claim 1, wherein the deactivating of the semi-persistent CSIreporting comprises: refraining from transmitting the one or moreadditional CSI reports.
 9. A wireless transmit and receive unit (WTRU),comprising: a transceiver configured to receive an indication toactivate a semi-persistent channel state information (CSI) reporting;and a processor configured to activate the semi-persistent CSI reportingfor a serving cell based on the received indication; wherein: thetransceiver is configured to transmit one or more CSI reports for theserving cell, after the semi-persistent CSI reporting is activated, andthe processor is configured to: determine that a time alignment timer(TAT) has expired, and deactivate the semi-persistent CSI reportingbased on expiration of the TAT.
 10. The WTRU of claim 9, wherein thereceived indication comprises any of: a downlink control information(DCI) format, or a random access response grant.
 11. The WTRU of claim9, wherein the processor is configured to: determine the serving cell ofa Physical Downlink Control Channel (PDCCH) on which the receivedindication is decoded; or determine the serving cell corresponding to aPhysical Downlink Shared Channel (PDSCH) on which the receivedindication is decoded.
 12. The WTRU of claim 9, wherein the processor isconfigured to determine a CSI request field from the receivedindication, wherein the CSI request field indicates activating ordeactivating the semi-persistent CSI reporting.
 13. The WTRU of claim 9,wherein the transceiver is configured to transmit the one or more CSIreports on a physical uplink shared channel (PUSCH).
 14. The WTRU ofclaim 9, wherein the transceiver is configured to transmit the one ormore CSI reports periodically.
 15. The WTRU of claim 9, wherein thereceived indication activates the semi-persistent CSI reporting based ondownlink control information (DCI) scrambled with a Radio NetworkTemporary Identifier (RNTI).
 16. The WTRU of claim 9, wherein theprocessor is configured to refrain from transmitting one or moreadditional CSI reports, when the semi-persistent CSI reporting isdeactivated.